Timeline for Can light produce weak gravitational waves?
Current License: CC BY-SA 3.0
8 events
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| Oct 20, 2014 at 23:42 | comment | added | CuriousOne | @Bencrowell: There is a real difference between assuming that a relatively trivial extrapolation of a theory into an untested parameter range is valid and actually doing the measurement to confirm that it's actually valid. I think it's a pretty good guess that GR gives the correct answer, but it's important to explain the difference between applying theory and confirming theory. | |
| Oct 20, 2014 at 21:59 | comment | added | user4552 | @CuriousOne: Unless somebody does the experiment there is no way of knowing. Not true. General relativity makes unequivocal predictions about this kind of thing, and it is a well tested theory. In particular, the gravitational fields made by light need not be weak, and we have direct evidence of this. The universe was radiation-dominated up until it was about 50,000 years old. This period includes the period of big-bang nucleosynthesis (BBN), so empirical data on BBN are a test of these cosmological models. Therefore we can confidently use GR to address this type of question. | |
| Oct 20, 2014 at 20:24 | comment | added | Qmechanic♦ | Related: physics.stackexchange.com/q/14064/2451 and links therein. | |
| Oct 20, 2014 at 20:21 | history | edited | Qmechanic♦ | CC BY-SA 3.0 |
gravity waves and gravitational waves are not the same thing
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| Sep 22, 2014 at 6:18 | history | tweeted | twitter.com/#!/StackPhysics/status/513935388176441346 | ||
| Sep 20, 2014 at 14:44 | answer | added | DaleSpam | timeline score: 2 | |
| Sep 20, 2014 at 14:17 | comment | added | CuriousOne | Unless somebody does the experiment there is no way of knowing. One can, however, apply the known theory to it (be it right or wrong) and the result of that is that cosmological redshifts are not the result of gravitational interaction of light with itself, it would be way too weak for that. Ultimately, of course, the redshift is the result of the interplay between spacetime and gravitating mass and one can use the observed redshifts to estimate the total amount of gravitating mass-energy of the universe (both normal and dark matter included). | |
| Sep 20, 2014 at 14:03 | history | asked | Dan | CC BY-SA 3.0 |